Method for preparing in-situ porous aluminum oxide membrane on insulated substrate

Abstract

The invention relates to a method for preparing an in-situ porous aluminum oxide membrane on an insulated substrate. The method is characterized by comprising steps of (1) plating a layer of 100nm-10mu m thick smooth aluminum membrane on the insulated substrate; (2) steeping the substrate plated with aluminum membrane obtained in step (1) in oxalic acid electrolyte for anodic oxidation in advance; (3) carrying out anodic oxidation through scanning, namely, taking the substrate anodized in advance in step (2) out of an electrolytic cell, removing adsorbed oxalic acid electrolyte through washing, shifting the oxalic acid electrolyte in the electrolytic cell out, putting the washed substrate back into the electrolytic cell, then pumping the oxalic acid electrolyte shifted out back to the electrolytic cell by a peristaltic pump at constant speed, keeping the liquid level of the electrolytic cell rising at constant speed, after the liquid level of the electrolyte sweeps over the whole pre-oxidized substrate from the bottom of the substrate at constant speed, sequentially anodizing unoxidized residual aluminum layer on the substrate in the pre-oxidizing step along with rising of the electrolyte at constant speed so as to obtain uniform high-quality in situ porous anodized aluminum membrane on the insulated substrate; and (4) oxidizing annealing. The method is simple and low in manufacture cost, and can be used for plating a large area of the in-situ porous anodized aluminum membrane on insulated substrates of various appearances.

Description

technical field [0001] The invention relates to a method for preparing an in-situ porous aluminum oxide film on an insulating substrate, in particular to a method for preparing a large-area nanoporous anodic aluminum oxide film on an insulating substrate in situ by combining high-purity aluminum evaporation with scanning anodic oxidation. Background technique [0002] Porous anodized aluminum prepared by anodizing high-purity aluminum is an important nanomaterial. It is not only widely used in the synthesis of nanomaterials, but also has a wide range of possible applications in optical antireflection and diffractive optical devices. Therefore, the in-situ preparation of large-area and high-quality porous anodic aluminum oxide films on optical substrates is a valuable optical thin film preparation technology. [0003] For the preparation of the in-situ porous anodic aluminum oxide film on the substrate at present, most of them are on conductive substrates such as silicon wafe...

AI Technical Summary

Problems solved by technology

[0003] For the preparation of the in-situ porous anodic aluminum oxide film on the substrate at present, most of them are on conductive substrates such as silicon wafers, ITO conductive glass and ITO glass sprayed with titanium (Nanotechnology, 13, (2002) 627-630 ; ACSNANO, 2, NO.11, (2008) 2250-2256), for most of the insulating substrates such as glass, fused silica, sapphire and other substrates, the usual anodic oxidation technology is directly plated on the above When the metal aluminum layer on the insulating substrate is electrochemically oxidized, it will be difficult to completely transform into a high-quality transparent aluminum oxide film layer due to the lack of the key role of the conductive substrate in transmitting the anodic oxidation current. Therefore, the prepared anodic aluminum oxide coating layer Poor optical transparency (Applied Surface Science, 257, (2011) 3307-3312; Advanced Materials Research, 179-180, (2011) 274-278), it is difficult to meet the requirements of optical devices for high optical transmittance of the film layer

Especially in the preparation of high-quality in-situ anodized aluminum film layer (after glass coating, the average transmittance of the sample in the visible light region is greater than 90%) on a large-area (5cm×5cm or more) insulating substrate, the usual anodic oxidation process more difficult to succeed

Images